May Weather in Philadelphia, United States

Last updated: June 24, 2025

In May, the average temperature in Philadelphia, United States is a pleasant 23°C (73°F). Temperatures can fluctuate significantly, with a minimum of 7°C (46°F) and a maximum soaring to 35°C (96°F). Visitors should be prepared for wet weather, as the area receives an average precipitation of 129 mm (5.1 in) over about 12 days. Additionally, the humidity hovers around a high 82%, adding to the tropical feel of the region.

May Temperature in Philadelphia

In May in Philadelphia, the average temperature is a pleasant 23°C (73°F). Maximum temperatures can reach up to 35°C (96°F), while minimum temperatures can drop as low as 7°C (46°F). This variation makes it essential for travelers to pack versatile clothing to enjoy both warm days and cooler evenings.

May Weather in Philadelphia: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Philadelphia, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Philadelphia, May typically has an average temperature of 23°C (73°F), with highs reaching up to 35°C (96°F) and lows dropping to around 7°C (46°F).

Data source: Temperature data for Philadelphia generated using information from the Copernicus Climate Change Service.

May Precipitation in Philadelphia

In Philadelphia in May, the total precipitation amount is 129 mm (5.1 in) over the course of 12 days.

May Precipitation Trends in Philadelphia

The chart displays monthly precipitation patterns in Philadelphia, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Philadelphia, May typically receives around 129 mm (5.1 inches) of precipitation spread over approximately 12 days.

Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

May Humidity in Philadelphia

In Philadelphia in May, humidity is 82%. With an average temperature of 23°C (73°F), this humidity feels like a warm, sticky embrace, making outdoor activities feel a bit more strenuous but offering a tropical ambiance perfect for leisurely strolls and relaxed sightseeing.

May Average Humidity in Philadelphia

This chart illustrates the average monthly humidity levels in Philadelphia, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Philadelphia is approximately 82%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Philadelphia

In Philadelphia in May, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Philadelphia.

Maximum UV Index Levels in Philadelphia for May

The chart shows the monthly maximum UV Index (UVI) for Philadelphia in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In May, the maximum UV index in Philadelphia typically reaches 11, which falls under the extreme exposure category.

Data source: Philadelphia May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How May Weather in Philadelphia Compares to Other Months

Weather in Philadelphia varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Philadelphia, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Philadelphia, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	9°C (48°F)	110 mm (4.3 inches)	85%	moderate
February Weather	11°C (53°F)	173 mm (6.8 inches)	84%	high
March Weather	15°C (60°F)	121 mm (4.8 inches)	82%	very high
April Weather	18°C (64°F)	158 mm (6.2 inches)	82%	very high
May Weather	23°C (73°F)	129 mm (5.1 inches)	82%	extreme
June Weather	26°C (79°F)	168 mm (6.6 inches)	79%	extreme
July Weather	27°C (81°F)	107 mm (4.2 inches)	82%	extreme
August Weather	27°C (80°F)	130 mm (5.1 inches)	77%	extreme
September Weather	25°C (77°F)	93 mm (3.7 inches)	74%	very high
October Weather	20°C (68°F)	106 mm (4.2 inches)	73%	very high
November Weather	12°C (54°F)	68 mm (2.7 inches)	85%	high
December Weather	10°C (51°F)	121 mm (4.8 inches)	88%	moderate